Magnetic floor coatings are known in the prior art. These floor coatings are typically applied directly in a layer thickness of, for example, 0.5 mm to a dried cementitious surface like a screed or concrete surface. Such a coated floor can be covered in the following with magnetic carpet or vinyl tiles. The magnetic interaction between the floor coating and the carpet tiles keeps the tiles fixed at their position. At the same time however, the carpet tiles can easily be exchanged, for example if the carpet is worn out or if the floor color shall simply be changed.
A coating composition suitable for such a purpose is described in EP 2 107 081 B1. This reference discloses a rubber composition for the production of an elastomer wherein the rubber composition comprises at least one rubber compound and at least one free-radical initiator. The rubber compound is cured by subjecting it to a radical cross-linking reaction. The rubber composition may further include magnetic or magnetizable particles.
It is, however, sometimes regarded as disadvantageous that the magnetic floor coating compositions which are known so far, can only be applied to dried surfaces. The ASTM F 2170-11 standard test method for determining relative humidity in concrete floor slaps, for example, states that “moisture permeating from concrete floor slabs affects the performance of flooring systems such as resilient and textile floor coverings and coatings” and that “excessive moisture permeating from floor slabs after installation can cause floor covering systems failures such as debonding and deterioration of finish flooring and coatings and microbial growth”. In practice it has usually been required that the relative humidity of a cementitious surface should be 75% or lower before a floor coating may be applied. In other words, the cementitious surface such as, for example, a screed or concrete surface has to be dried for a certain period of time before a flooring coating layer such as a magnetic floor coating can be applied. This does not only include a waiting period which delays using the respective room, but also requires continuous determination of the actual humidity.
It is therefore an object of the present invention to develop a method for providing a surface with a layer of a magnetic and/or magnetizable cover composition that can be applied to cementitious surfaces with a higher level of humidity and that thus overcomes the drawbacks of the prior art.
This object is solved by a method for providing a surface, in particular a floor surface, with a layer of a magnetic and/or magnetizable cover composition, the surface having at least one layer of cementitious material, wherein the method comprises the step of spreading the layer of the cover composition onto the surface, the cover composition comprising a polymeric binder and magnetic and/or magnetizable particles, wherein the layer of the cover composition has a water-vapor transmission rate of at least 0.25 g h−1 m−2 according to ASTM D1653, and the surface and/or the layer of cementitious material has a relative humidity of more than 75% according to ASTM F 2170-11.